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Re: Large # of rows in query extremely slow, not using

From: Kris Jurka <books(at)ejurka(dot)com>
To: Stephen Crowley <stephen(dot)crowley(at)gmail(dot)com>
Cc: pgsql-performance(at)postgresql(dot)org
Subject: Re: Large # of rows in query extremely slow, not using
Date: 2004-09-23 23:47:59
Message-ID: Pine.BSO.4.56.0409231840280.18935@leary.csoft.net (view raw or flat)
Thread:
Lists: pgsql-performance

On Thu, 23 Sep 2004, Stephen Crowley wrote:

> Thanks for the explanation. So what sort of changes need to be made to
> the client/server protocol to fix this problem?

The problem is that there is no way to indicate why you are using a 
particular statement in the extended query protocol.  For the JDBC driver 
there are two potential reasons, streaming a ResultSet and using a server 
prepared statement.  For the streaming as default case you desire there 
needs to be a way to indicate that you don't want to create a generic 
server prepared statement and that this query is really just for one time 
use, so it can generate the best plan possible.

Additionally you can only stream ResultSets that are of type FORWARD_ONLY.  
It would also be nice to be able to specify scrollability and holdability 
when creating a statement and the offset/direction when streaming data 
from a scrollable one.

Kris Jurka

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